Tubing anchor



Aug. 2, 1932. T. L. LYNCH TUBING ANCHOR Filed April 15, 1929 Patented Aug. 2, 1932 ETE ar-as THEODORE L. LYNCH, OF OXNARD, CALIFORNIA TUBING ANCHOR Application filed April 15,

This invention relates to a tubing anchor by means of which tubing may be positioned and retained in position within a casing of a well. The tubing anchor embraced by this invention may be set manually ormay be operated automatically, whenever tubing breaks or suddenly drops within a well casing.

Although the device embraced by this invention may be utilized in the drilling and s in the operation of various forms of wells, it will be particularly described as applied to use in the oil industry. In all wells requiring the use of tubing it isa dangerousand expensive practice to placethe tubing inside the casing without some means of protecting' against. the accidental dropping'of the tubing to the bottom of the hole. accidental parting of the tubing or wire line, or any failure on the part of rigging employed a during manipulation of the tubing, the tubing may automatically fall to the bottomv of the hole and become so distorted and jammed that it is impossible to withdraw the tubing from the hole. Very often the dropping of a string of tubing may cause the abandoning of the well. l

By placing a tubing anchor or a device of the character employed by this invention,

(which is both a tubing anchor and a tubing '30 catcher) in a string of tubing, the accidental dropping of tubing within a casing ofthe Well is positively obviated. An object of this invention is to disclose and provide atubing anchor of simple construction. Another object is to disclose'and provide a tubing anchor which is relatively short and can therefore be used in very crooked holes without damage.

Another object is to disclose and provide a tubing anchor which can be manually operated and set at any desired point in a casmg. i

A still further objectis to disclose and provide a device which can be caused to anchor 5 tubing by manual operation at any desired point in a casing. and to also function automatically as a tubing anchor.

A still further object is to disclose and provide a tubing anchor and catcher which is positive in its action and which operates very In case of section, of the devlce 1n operatlve positlon I Fig. 3 is a horizontal section taken through 1929. Serial'No. 355,081.

quickly. It is an object of thisinvention to disclose and provide a tubing catcher which will catch-and retain tubing within acasing before the tubing has fallen any appreciable distance and before a large momentum has been developed by such fall. I

Furthermore, it is an object of this invention to provide a tubing anchor by meansof which tubing may be positively centered and operated in acasing without the use of springs. Other objects, uses andadvantages of the device embraced by this invention will becomeapparent to those skilled inthe art from the following detailed description, reference being had to the appended drawing, in which:

Fig. 1 is a side elevation, partly in vertical upon tubing being lowered into a well casing.

Fig.2 is a vertical section through the device, tubing and casing, showing the position of the parts when the device automatically anchors tubing in a casing.

the device along a plane indicated by line 5 Fig. 4 is a horizontal section taken through a modified form of 'wedging head.

Fig, 5 is a vertical section through the device, showing a modified form of construction. 1

Referring to thedrawing, the device may be attached to tubing-1 which is to be lowered into a casing 2. The device itself comprises a section of tubing 3 having a wedging head 7 4- rigidly attached theretoas, for example, by welding. The wedging head 4: may be provided with dove-tailed guides 5 attached to, the wedging head l in any suitable manner, as for example. by means of the machine 0 screws 6. If desired, the dove-tailed guides may be formed integrally with the wedging head 4:.

Anchor slips 7 may be slidably mounted upon the guides 5, the anchor slips 7 being provided with serrated faces 8 so as to permit the faces of the anchor slips to engage with the casing and prevent downward movement of the tubing within the casing. Preferably, the serrations on the faces ofthe anchor members 7 are slightly inclined to the longitudinal axis of the section of tubing 3, so that when said slips contact with the interior surface of the casing 2, a slight shearing force is exerted instead of a direct downward thrust. This will allow the anchor to be released with less effort.

Preferably, the anchor slips are provided with downwardly extending narrow lugs or fingers 9, passing between outwardly extending lugs 10 attached to or made a part of the wedging head 4 or the guides 5. These lugs 10 preferably contact with the enlarged portion of the anchor slips 7 and thereby prevent said anchor slips 7 from moving below the predetermined position or point on the guides 5.

Below the wedging head 4 a cam retaining ring or shoe supporting ring 11 is slidably mounted upon the section of tubing 3. The cam retaining ring 11 is preferably provided with a plurality of cams or cam shoes 12 pivotally connected as at 13 to lugs 14, formed in the ring 11. The shoes or cams 12 may be provided with a curved contacting face which may be knurled or serrated. Said serrated contacting face may be formed in a parabolic curve, presenting a double curved surface as that of a modified sphere, for purposes to be described later.

The cam or shoes 12 are preferably connected to or made a part of a lug 14 extending inwardly toward the section of tubing 3, downward movement of lug 14 causing an outward movement of the shoe 12 by reason of the eccentrically postioned pin or pivot indicated at 13.

Between the wedging head 4 and the shoe ring 11 a weight 15 may be loosely positioned upon the section of tubing 3. Preferably, the weight 15 is of such size that when the ring 11 is in contact with the collar 16, or other collar which limits the distance of tubing on which the ring 11 and weight 15 are freely movable), the upper surface of edge of the weight 15 is slightly spaced away from the extensions 9 of the anchor slips 7 as such anchor slips are supported upon the lugs 10.

The collar 16 may be threadedly engaged, as indicated at 17 to the lower end of the section of tubing 3 and may also be provided with internally cut threads 18 adapted to engage with another portion of the tubingil. Preferably, the upper end of the collar 16 is provided with a suitable form of cam, for example, a: number of ratchet depressions 19, and the lower portion of the shoe or cam ring 11 is also provided with a plurality of ratchet depressions adapted to cooperate with the ratchet formed on the collar 16. If desired, however, the ratchet depressions 19 formed in the ring 11 may cooperate with a collar or ring rigidly attached to the section of tubing 3 above an ordinary collar which is then used to merely connect the section of tubing 3 to the ordinary tubing 1.

As shown in Fig. 4, the wedging head 4, instead of being provided with a plurality of flat faces such as the dove-tailed guides 5, may be provided with a plurality of ribs 20 terminating in circular heads 21 of greater diameter than the thickness of the ribs 20. The anchor slips 7 may then be formed with circular grooves adapted to slidably receive the circular protuberances 21 on the ends of ribs 20. This modified construction permits the anchor slips 7 to slightly pivot upon an axis extending through the center of the circular protuberances 21.

The operation of the device is as follows: The device is connected to the tube 1 by means of the collar 16 and by means of an ordinary collar 22, and the tubing is then lowered into the casing 2. The shoes or cams 12 contact with the interior surfaces of the casing 2, being urged outwardly by reason of the weight 15 contacting with the ends of the lugs 14 which are a part of the shoes 12.

It will be understood that any number of shoes or cams 12 may be employed on a ring, but four shoes or more are preferred, as then the tubing is perfectly centered within the casing, and if one of said shoes is broken off, there is a sufficient number of shoes left to still properly cause the device to function.

Inasmuch as casings are of a standard outer diameter, but vary in internal diameter depending upon the thickness of the walls, it will be seen that such variations in internal diameter are readily taken care of by the construction of the shoes described herein. The outer serrated faces of the cams 12 are curved, as has been described, and being pivoted at 13 they contact with the interior surfaces of the casing upon substantially constant areas.

It will be understood that the ring 11 carrying the shoes 12 and the weight 15 is loosely mounted upon the section of tubing 3, and normally the weight 15 when in contact with the lugs 14 of the shoes 12 carried by the ring 11 is spaced from the lower ends of extensions 9 attached to the anchor slips 7. The area of the shoes 12 in contact with the interior of the casing and the mass or weight of the weight 15 are preferably so adjusted that the friction between the shoes and the casing 2 is sufficient to cause the shoes, the shoe ring 11. and the weight 15 to drift slowly down the interior of the casing, without the application of any positive downward force. Preferably the normal dri ting speed of the shoe ring 11 and the weight 15 within a casing 2 is substantially equal to or slightly in excess of the normal speed at which tubing is normally or ordinarily lowered into a well or casing.

After the tubing, carrying the device herein described, has reached the proper level,

ample, the cam shoes 12 may extend upwardly from the pivot 13 instead of downwardly as shown in the drawing. Furthermore, instead of having the ratchet. depressions 19 made in the upper end of a collar 16, such ratchet depressions may be made a part of a separate and distinct collar firmly attached to the section of tubing 3. The particular construction and design of the wedging head 4, or the guides 5, also is immaterial, the construction shown in the drawing being very effective.

The lugs or holders 10 adapted to support the anchor slips 7 need not be made part of the guide 5, but instead may be made a part of either the section of tubing 3 or the wedging head 4. Furthermore, the number of shoes or anchor slips used is optional, although as has been stated before, four or more is preferred. All changes and modifications coming within the scope of the appended claims are embraced thereby.

I claim:

1. In a device of the character described, the combination of a section of tubing, 21 wedging head positioned on said tubing, anchor slips slidably mountedupon and carried by said wedging head, said slips being provided with serrations on their faces inclined at the axis of said tubing, a ring movably positioned upon said tubing and below said wedging head, a plurality of spaced friction shoes pivotally connected to said ring, a weight slidably positioned on said tubing above said ring, means operably connecting said shoes and weight to cause said weight to force said shoes outwardly from said tubing, and means for limiting movement of said ring longitudinally upon said tubing.

2. In a device of the character described, the combination of a section of tubing, a

wvedging head positioned on said tubing, an-

chor slips slidably mounted upon and'carried by said wedging head, said anchor slips being provided with serrations on their faces inclined tothe axis of said tubing, a ring movably positioned upon said tubing and below said wedging head, a weight slidably positioned on said tubing and above said ring, cam shaped friction shoes carried by said ring and adapted to present substantially constant friction surfaces at varying distances from said ring, and means for limiting movement of said ring longitudinally upon said tubing.

' 8. In a device of the character described, the combination of a section of tubing, a wedging head positioned on said tubing, anchor slips slidably mounted upon and carried by said wedging head, a ring movably positioned upon said tubing and below said wedging head, cam shaped friction shoes carried by said ring and adapted to present substantially constant friction surfaces at varying distances from said ring, a weight slidably positioned on said tubing and above said ring and in operable contact with said cam shaped shoes, and a cam mounted on said tubing below said ring and adapted to cooperate therewith.

4. In a device of the character described, the combination of a section of tubing, 21 wedging head positioned on said tubing, a plurality of anchor slips slidably mounted upon and carried by said wedging head in spaced relation, said slips being provided with serrations on their faces and with downwardly extending fingers, a ring movably positioned upon said tubing and below said wedging head, a plurality of spaced friction shoes pivotally connected to said ring, a weight slidably positioned on said. tubing above said ring, and in operable contact with said shoes, and means for limiting longitir dinal movement of said ring upon said tubing.

5. A tubing anchor comprising a section of tubing, within a casing, a wedging head positioned on said tubing, anchor slips slid ably mounted upon and carried by said wedg ing head, a ring movably positioned upon said tubing and below said wedging head, a plurality of cam shaped friction shoes car riedby said ring and adapted to present sub stantially constant friction surfaces at vary ing distances from said ring, a weight slidably positioned on said tubing above said ring, and in operable contact with said shoes, and a cam mounted on said tubing below said ring and adapted to cooperate therewith to raise said ring and weight, and actuate said slips when said tubing is rotated.

6. In a device of the character described, a section of tubing, a wedging head positioned on said tubing, anchor slips slidably mounted upon and carried by said wedging head, a ring freely slidable on said tubing below said wedging head, friction means pivotally carried by said ring and adapted to present substantially constant friction surfaces at varying distances from said ring, and a stop mounted on said tubing below said ring on which said ring may rest out of contact with said slips, said ring being adapted to move along said tubing into operative contact with said slips, to actuate said slips to engage a casing in which said device is used upon uncontrolled downward movement of the tubing.

7. In a device of the character described, a section of tubing, a wedging head positioned on said tubing, anchor slips slidably mounted upon and carried by said wedging head, a ring freely slidable on said tubing below said wedging head, friction means pivotally carried by said ring and adapted to present substantially constant friction surfaces to a casing in which said device is used at varying distances from said ring, and a cam llC lli

lit

mounted on said tubing below said ring on which said ring may rest out of contact with said slips, said ring being adapted to move along said tubing into operative contact'with said slips, to actuate said slips to engage a casing upon uncontrolled downward movement of the tubing.

8. In a device of the character described, a section of tubing, a wedging head positioned on said tubing, anchor slips slidably mounted upon and carried by said wedging head, a ring freely slidable on said tubing below said wedging head, friction means pivotally carried by said ring and adapted to present substantially constant friction surfaces to a casing in which said device is used at varying distances from said ring, and a cam mounted on said tubing below said ring on which said ring may rest out of contact with said slips, said ring being adapted to move along said tubing to actuate said slips to engage a casing upon uncontrolled downward movement of the tubing, said cam being adapted to selectively raise said ring into operative contact with said slips to cause engagement thereof with a casing.

9. In a device of the character described, a section of tubing, a wedging head carried by said tubing, anchor slips slidably mounted upon and carried by said wedging head, said slips being provided with serrations on their faces inclined to the axis of said tubing, a ring freely slidable on said tubing below said wedging head, a plurality of spaced shoes pivotally connected to said ring, said shoes being provided withserrated faces adapted to produce substantially uniform frictional contact with a casing in which said device is used at varying instances from said ring, and a cam mounted on said tubing below said ring on which said ring may rest out of contact with said slips, said cam being adapted to selectively raise said ring into operatlve contact with said slips to cause engagement thereof with a casing.

10. In a device of the character described, a section of tubing, a wedging head carried by said tubing, anchor slips slidably mounted upon and carried by said wedging head, said slips being provided with serrations on their faces inclined to the axis of said tubing, a ring freely slidable on said tubing below said wedging head, a plurality of spaced shoes pivotally connected to said ring,rsaid shoes being provided with serrated faces adapted to produce substantially uniform frictional contact with a casing in which said device is used at varying distances from said ring, and a cam mounted on said tubing below said ring on which said ring may rest out of contact with said slips, said cam being adapted to selectively raise said ring into operative contact with said slips to cause engagement thereof with a casing, said ring being adapted to move along said tubing to actuate said slips to engage a casing when said tubing moves downwardly at a speed in excess of a predetermined speed.

11. In a device of the character described,

the combination of a section of tubing, a

wedging head positioned on said tubing, anchor slips slidably mounted upon and carried by said wedging head, a ring freely slidable on saidtubing below said wedging head, friction means pivotally carried by said ring and adapted to present substantially constant friction surfaces to a casing in which said i 

